Objective:
The objective of this blog is to share the information about the new database parameter and hidden parameter introduced in 21c along with the deprecated and obsolete database parameter.
The parameters are the backbone of the database that is responsible for running the database with full utilized I/O operations. The database parameters can be modified in the system or session level. Some of the parameters can be altered in memory level and do not require any database restart, and some are not which requires a database to restart to get reflect for the database instance.
Oracle Database Parameters are the predefined values set for various memory segments and information on different location of files and log files for bringing up the database instance. Deprecated parameter means the parameter that is being replaced by a better alternative and shouldn’t be used, and obsolete parameter means the parameters are removed from the database and no longer in use.
The Oracle Database Hidden parameter must not be changed without taking concern from Oracle support, changing the hidden parameter value may result in higher performance degradation and also serious corruption issue. Please go through the Metalink Doc ID 315631.1 for more information.
Note: The database parameter mentioned here are compared with respect to the previous production release database version 19c.
Now let’s begin to have the information on Oracle Database Version 21c parameters.
New Parameter introduced in Version 21c in comparison to 19c
| NAME | ISDEP | DESCRIPTION |
|---|---|---|
| _gc_policy_time | FALSE | how often to make object policy decisions in minutes |
| _gc_undo_affinity | FALSE | if TRUE, enable undo affinity |
| allow_deprecated_rpcs | FALSE | allow deprecated rpcs |
| auto_start_pdb_services | FALSE | Automatically start all PDB services on PDB Open |
| blockchain_table_max_no_drop | FALSE | maximum idle retention minutes for blockchain tables |
| container_data | FALSE | which containers should data be returned from? |
| dbnest_enable | FALSE | database Nest enable |
| dbnest_pdb_fs_conf | FALSE | PDB Filesystem configuration |
| diagnostics_control | FALSE | controls response when 'enabling diagnostics' privilege is absent |
| drcp_connection_limit | FALSE | DRCP connection limit |
| drcp_dedicated_opt | FALSE | Turn on/off dedicated optimization for DRCP |
| enable_per_pdb_drcp | FALSE | Turn on/off per PDB DRCP |
| heartbeat_batch_size | FALSE | Number of heartbeats to be sent in a batch |
| ignore_session_set_param_errors | FALSE | Ignore errors during alter session param set |
| inmemory_deep_vectorization | FALSE | In-Memory Deep Vectorization Enabled |
| kafka_config_file | FALSE | KSR pub/sub external message bus(KSRPS) CONFIGuration file |
| mandatory_user_profile | FALSE | Enforce Mandatory Password Profile for multitenant database |
| max_auth_servers | FALSE | Maximum size of auth pool |
| min_auth_servers | FALSE | Minimum size of auth pool |
| native_blockchain_features | FALSE | Native block chain enable/disable |
| optimizer_capture_sql_quarantine | FALSE | enable automatic creation/update of sql quarantine configuration |
| optimizer_cross_shard_resiliency | FALSE | enables resilient execution of cross shard queries |
| optimizer_real_time_statistics | FALSE | optimizer real time statistics on conventional DML |
| optimizer_session_type | FALSE | Controls Auto Index |
| optimizer_use_sql_quarantine | FALSE | enable use of sql quarantine |
| pkcs11_library_location | FALSE | PKCS#11 library location for Transparent Data Encryption |
| pmem_filestore | FALSE | Persistent Memory Filestore list |
| resource_manager_cpu_scope | FALSE | scope of CPU resource management |
| result_cache_execution_threshold | FALSE | minimum executions before a PL/SQL function is cached |
| result_cache_max_temp_result | FALSE | maximum temp per result as percent of total temp for result cache |
| result_cache_max_temp_size | FALSE | maximum amount of temp space to be used |
| shard_queries_restricted_by_key | FALSE | add shard key predicates to the query |
| tablespace_encryption_default_algorithm | FALSE | default tablespace encryption block cipher mode |
| tde_key_cache | FALSE | Enable caching of TDE intermediate key |
| timezone_version_upgrade_online | FALSE | enable/disable time zone version upgrade online |
New Hidden parameter introduced in Version 21c in comparison to 19c
| PARAMETER | PARAMETER_DESCRIPTION |
|---|---|
| _STFForceTranslateOracleSQL | if TRUE translation profile will translate Oracle SQL statements |
| __db_pmem_direct_map_size_metadata | Size of PMEM memory metadata of DEFAULT buffer pool for standard block size buffers |
| __sess_template_test_attrs | session template: include test attributes |
| _adaptive_scalable_log_writer_evaluation_fraction | Serial/parallel log writer evaluation fraction (in 10000ths) |
| _adaptive_scalable_log_writer_evaluation_interval | Serial/parallel log writer evaluation interval (in seconds) |
| _age_block_batch_timeout_ms | timeout before shipping out the batched age blockmessages in milliseconds |
| _alert_segment_size | Alert-log segment size in MBs (1024*1024) |
| _alert_segment_textfile | Alert-log text-file also to be segmented |
| _alert_segments_max | Alert-log max segments to retain, 0 for unlimited |
| _allow_cross_version_chunk_move | Oracle internal parameter |
| _allow_fallback_to_dbkey | if TRUE, allow fallback to dbkey |
| _allow_privileged_session_dblink_conn | Allow privileged session for dblink connection |
| _allow_triggers_on_vpd_table | Allow triggers on VPD protected table in DML |
| _allow_xdb_anonymous_logon | Allow XDB anonymous logon |
| _allowed_pvf_owners | List of schemas allowed to own password verification function |
| _aq_queue_global_service | AQ queue global service |
| _aq_tm_processes_dump_interval | Time(minutes) between consecutive Dumps in alert log |
| _aqsharded_cached_hint | sharded queue cached hint |
| _aqsharded_enq_fresh_ptn_reload | start enqueueing to a fresh partition on reload |
| _aqsharded_lowmem_timeout | sharded queue low mem timeout (in centiseconds) |
| _aqsharded_reload_tune | sharded queue tune reload behaviour |
| _asm_allow_appliance_offlineonline | Allow OFFLINE/ONLINE DISK/FAILUREGROUP on ASM Appliances |
| _asm_buffer_overlap_tracer | Enables kfioBufOverlapTracer |
| _asm_diskgroup_renew_timeout | timeout FENC will give former ASMB group owner to renew |
| _asm_dump_split_pw | Seconds to wait before requesting dump of split pending writes |
| _asm_enable_map_share | Enable ASM extent map share |
| _asm_enable_vfreloc_on_rm | Enable voting file relocation on rolling migration |
| _asm_frag_threshold | Percentage threshold before disk/diskgroup is deemed fragmented |
| _asm_hard_check | H.A.R.D. check buffer before write operation |
| _asm_iosfailover_freq | Frequency limit after which db gives up on failing over to IOS |
| _asm_iosfailover_timeout | Time window within which db tries to failover to IOS |
| _asm_max_kfsg_free_heap_perc | Max percentage of SGA memory reserved for kfsga free heap |
| _asm_max_kfsg_free_heap_size | Max buffer size reserved for kfsga free heap |
| _asm_max_occupied | Maximum percentage of disk occupied to check for fragmentation |
| _asm_min_occupied | Minimum percentage of disk occupied to check for fragmentation |
| _asm_node_number | ASM node number |
| _asm_offline_wait_timeout | Timeout for offline wait |
| _asm_ownerid_trace_timeout | ownerid tracing threshold in seconds |
| _asm_pst_rsinfo | file redundancies to consider during PST liveness checks |
| _asm_scrub_max_cod_wait | Number of minutes to delay scrub COD recovery |
| _asm_shared_pool_latch_timeout | seconds before terminating inst if ASMB is waiting for shared pool latch during shutdown |
| _asm_showpdb_asmtbl | Allow asm table values to be shown in pdb |
| _asm_write_cancel_timeout_percentage | Percentage of the write timeout to wait before optional offline |
| _asm_xrov_cachelgio | ADVM cache large IO |
| _assert_single_current_buffer | if TRUE, check and assert only one current buffer |
| _assm_auto_tracing_threshold | ASSM threshold to start space search tracing |
| _auto_mv_enabled | enable/disable Auto MV logic in the sql access advisor |
| _autoptn_costing | DBMS_AUTO_PARTITION is compiling query for cost estimates |
| _autoptn_flags | DBMS_AUTO_PARTITION flags |
| _autoptn_translate_table_name | DBMS_AUTO_PARTITION table name translation |
| _autoptn_workload_id | DBMS_AUTO_PARTITION workload id |
| _autosts_capture_control | internal controls for auto STS capture |
| _autosts_long_interval | Auto STS long flush interval |
| _autosts_retention_interval | Auto STS retention interval |
| _autosts_short_interval | Auto STS short flush interval |
| _aux_storage_size | Auxillary storage for PDB. |
| _awr_data_masking | Enable/Disable AWR data masking functionality |
| _backup_interrupt_wait_time | specifies interrupt wait time in centi seconds |
| _bct_public_dba_buffer_dynresize_delay | control frequency of dynamic resizing of public dba buffers |
| _bigdata_offload_flag | BigDataSQL offload flag |
| _block_change_tracking_file | file location for broker to reenable BCT |
| _blockchainHeapSize | Set the heap size in bytes for blockchain |
| _blockchainTracing | Set tracing for blockchain |
| _blockchain_forced_off | force off blockchain |
| _blockchain_txn_apis_enabled | If true, the txn layer blockchain API'S kick in |
| _blockchain_txn_test_lvl | blockchain txn test lvl |
| _boc_mode | Broadcast-on-commit mode |
| _boc_rdma_wait_time | BOC RDMA busy wait time (microseconds) |
| _buffer_requests_to_drain | Buffer for requests to drain before planned failover |
| _bypass_sensitive_context | bypass sensitive handling for specific SYS_CONTEXT() parameters |
| _cdb_init_batch_size | Batch size for reading pdb info during CDB mount |
| _cdb_svlt_use_tcps | Use TCPS for CDB Servlet |
| _cell_metadata_compression | Cell metadata compression strategy |
| _cell_offload_vector_groupby_external | enable cell offload of vector group by with external tables |
| _cgs_clscevents_dumpinterval | cgs clsce events statistics dump interval in seconds |
| _cgs_publish_netinfo_collect_event_chmjf | enable cgs publish collect_netinfo event to event stream for CHM with CHM'S JASON format |
| _cgs_publish_netinfo_collect_event_chmjf_batchsz | batch size of cgs events publishing to CHM in json format via clsce event stream |
| _cgs_query_net_interface | api to query network interface |
| _cloud_mandatory_profile_setup | Mandatory Profile Setup for Multitenant Cloud Environment |
| _cluster_database_instances | number of instances to use for sizing cluster db SGA structures |
| _connect_string_settings_after_logon_triggers | set connect string session settings after logon triggers |
| _connect_string_settings_unalterable | make connect string session settings unalterable |
| _connstr_test_param | connect string workload behavior spare param |
| _consensus_follower_election_timeout | consensus follower's election timeout |
| _consensus_leader_heartbeat_interval | consensus leader's heartbeat interval |
| _consensus_leader_maximum_heartbeats | consensus leader's maximum heartbeats |
| _consensus_queue_maximum_elements | consensus queue maximum elements |
| _consensus_slaves_maximum_count | consensus slaves maximum count |
| _cp_del_free_sess | connection pool: delete free sessions when at PDB limit |
| _cp_del_free_sess_limit_secs | connection pool: delete free sessions time limit (in seconds) |
| _cputime_limit_parallel_fptr | CPU-time limit for for parallel first-pass recovery |
| _create_pdb_disable_mirror_reads | Disable mirror reads during create pdb |
| _create_pdb_flashback_barrier | force flashback barrier for create pdb |
| _cross_con_remove_pushed_preds | remove pushed predicates from query fetching across containers |
| _ctas_numfrags_hint | Hint for number of partition fragments to be loaded in a CTAS |
| _ctex_fk_copy_mode | Create table for exchange Copy mode for referential constraints |
| _datapump_bypass_tstz_check | Bypass Data Pump TSTZ version checking during import. |
| _datapump_hide_cdb_warning | Hide Data Pump warning for CDB$ROOT and PDB$SEED |
| _db_cache_advice_size_submultiple | cache advisory size submultiple |
| _db_cache_pmem_confidence_try | DB Cache PMEM buffer promote attempts for greater confidence |
| _db_cache_pmem_promotion_touch_rate_reset_interval | DB Cache PMEM promotion touch rate reset interval in sec |
| _db_cache_pmem_promotion_touch_rate_threshold_time | DB Cache PMEM promotion touch rate threshold time in sec |
| _db_cache_pmem_touch_rate_compare_per | DB Cache PMEM buffer touch rate additive percentage when comparingagainst dram touch rate |
| _db_cache_pmemp_len | DB Cache PMEM promotion list max length |
| _db_cache_xmem_promotion_algo_chosen | DB Cache Xmem/Pmem promotion algo |
| _db_nvm_promotion_deferred_tchcnt | touch count threshold which allows deferred background based nvm buffer promotion |
| _db_pmem_auto_resize_interval | PMEM auto resize interval in minutes |
| _db_pmem_direct_map_size | Size of direct mappable PMEM buffer cache |
| _db_replay_security_config | Database Replay Security Configuration |
| _dbnest_resource_opts | dbNest - resource options |
| _dbnest_skip_fed_root | Fed root is skipped so CDB nest is root of all pdbs |
| _dbopen_breakpoint | ALTER DATABASE OPEN codepath breakpoint |
| _dbreplay_mpk_key | Database Replay Package Key |
| _ddlapply_enable | DDL VIA APPLY Enable |
| _default_ini_trans_index | Default value of INI_TRANS enforced by DWCS lockdown for indexes |
| _default_ini_trans_table | Default value of INI_TRANS enforced by DWCS lockdown for tables |
| _default_oracle_fs_type | default file system type for an oracle file system |
| _default_service | Run default service |
| _defer_rcv_pdb_attach | Defer PDB domain attach in instance recovery |
| _defer_rewrap_controlfile_key_history | if TRUE, defer rewrap control file TS keys under next PDB open |
| _dgb_dgpdb_appst | DGPDBs with apply state off |
| _dgpdb_file_name_convert | datafile name convert patterns and strings for per PDB standby |
| _dgpdb_standby_controlfile_name | a name template with three %u's for DGPDB standby controlfile |
| _direct_io_via_mapped_pmem | if TRUE, direct path I/O will attempt to memory map files on PMEM |
| _disable_block_corruption_track | disable block corruption tracking |
| _disable_foreign_scn_adjust | Disable foreign SCN adjustment |
| _disable_ilm_internal | Force disable internal ilm stats and drop ilm segment |
| _disable_mandatory_profile_onclone | Disable Mandatory Profile check on clone of a PDB |
| _disable_marking_noops | Don't mark any captured statements as no-ops. |
| _disable_orphan_pdb_recovery | Disable PDB PITR/FB to orphan PDB incarnation |
| _disable_pdb_space_check | Disable pdb storage usage check in the session |
| _disable_sga_filedel | disable deletion of files used for SGA |
| _dmm_ser_test | Stress testing for serialized models |
| _dmm_xgboost_max_memory | xgboost maximum memory |
| _dp_force_length_semantics | Force nls length semantics |
| _dynamic_hash_bucket_array | dynamic hash bucket array |
| _dynamic_processes_force_timeout | dynamic process force timeout |
| _dynamic_processes_max_oom_timeout | dynamic process max timeout for out of memory |
| _dynamic_processes_wait_timeout | dynamic process wait timeout for new process |
| _eighteenth_spare_pdb_parameter | eighteenth spare pdb parameter - integer |
| _eighth_spare_pdb_parameter | eighth spare pdb parameter - integer |
| _eighty-second_spare_parameter | eighty-second spare parameter - string |
| _eleventh_spare_pdb_parameter | eleventh spare pdb parameter - integer |
| _enable_bug_29838374 | enable/disable bug fix 29838374 |
| _enable_cdb_all_sync | Is CDB-wide ALL sync enabled |
| _enable_dbwr_parallel_invalidations | if TRUE, enables flush and invalidate by DBWRs |
| _enable_dynamic_processes | dynamic process SOs |
| _enable_fsdirect_odmlib | enable or disable FsDirect static ODM library |
| _enable_fsdirect_pin | enable direct pin of FsDirect blocks |
| _enable_fsdirect_rac | enable FsDirect in RAC |
| _enable_gsm_listener_networks | gsm listener in listener networks |
| _enable_ignorable_error_capture | Capture statement if error is ignorable |
| _enable_increase_lms_process | set to true to allow _increase_lms_process changes |
| _enable_load_from_clone | Is load from a Root Clone allowed |
| _enable_log_memory_protection_key | enable memory protection keys (log) |
| _enable_memory_protection_keys | Enable memory protection keys usage |
| _enable_mle | enable MLE |
| _enable_pdb_skiplist_recovery | Enable pdb skip list setup during media recovery. |
| _enable_pdb_skiplist_redogen | Enable pdb skip list setup during redo generation. |
| _enable_per_container_acl | Enable Per Container ACL |
| _enable_pmem_direct_cache | if TRUE, enable PMEM direct mapped buffers |
| _enable_pmem_exchange | if TRUE, enable PMEM exchange during promotion |
| _enable_pmem_prefetch | if TRUE, enable prefecting from PMEM |
| _enable_ptime_update_for_sys | Enable/Disable update of user$ for sys |
| _enable_tenant_id_check | Enable Tenant Id check for database link |
| _enable_tenant_id_transfer | Enable Tenant Id transfer |
| _enable_unified_memory | Enable use of unified PGA pool |
| _endprot_stack_segments | overrun protection for kgh stack segments |
| _enforce_minimum_password_rollover_time | Enforce minimum PASSWORD_ROLLOVER_TIME of one hour |
| _enqueue_wall_clock_time | if TRUE, use KSUFTIME timer |
| _exa_pmemlog_threshold_usec | maximum i/o time (usecs) for enabled Exadata PMEMLog |
| _failover_svrcsum | enable server checksum to optimize failover |
| _fb_log_max_rereads | Maximum number of rereads after reading a corrupt flashback block |
| _fb_recovery_slave_count | Number of recovery slaves to be used by the FLASHBACK DATABASE |
| _fbda_adv_gbl_bscn_bcast_interval | flashback archiver broadcast interval to advance global barrier SCN |
| _ffs_in range_scan_threshold | threshold of min percentage of block read to use ffs in rs |
| _fifteenth_spare_pdb_parameter | fifteenth spare pdb parameter - integer |
| _fifth_spare_pdb_parameter | fifth spare pdb parameter - integer |
| _fiftieth_spare_pdb_parameter | fiftieth spare pdb parameter - string list |
| _fifty-eighth_spare_pdb_parameter | fifty-eighth spare pdb parameter - boolean |
| _fifty-fifth_spare_pdb_parameter | fifty-fifth spare pdb parameter - boolean |
| _fifty-first_spare_pdb_parameter | fifty-first spare pdb parameter - boolean |
| _fifty-fourth_spare_pdb_parameter | fifty-fourth spare pdb parameter - boolean |
| _fifty-ninth_spare_pdb_parameter | fifty-ninth spare pdb parameter - boolean |
| _fifty-second_spare_pdb_parameter | fifty-second spare pdb parameter - boolean |
| _fifty-seventh_spare_pdb_parameter | fifty-seventh spare pdb parameter - boolean |
| _fifty-sixth_spare_pdb_parameter | fifty-sixth spare pdb parameter - boolean |
| _fifty-third_spare_pdb_parameter | fifty-third spare pdb parameter - boolean |
| _first_spare_pdb_parameter | first spare pdb parameter - integer |
| _fixup_all_apps | Callback to fix up replay state of all applications |
| _fixup_app_pdb_status_in_root | application name whose PDB application status should be fixed up |
| _fixup_cdb_apps | Callback to fix up replay state of CDB-wide applications |
| _force_dax_io_err | Force I/O error on online/standby redo log |
| _force_pmem_direct_mapped_cache_scan | if TRUE, force PMEM mapped direct path scan to cache path scan |
| _fortieth_spare_pdb_parameter | fortieth spare pdb parameter - string |
| _forty-eighth_spare_pdb_parameter | forty-eighth spare pdb parameter - string list |
| _forty-fifth_spare_pdb_parameter | forty-fifth spare pdb parameter - string list |
| _forty-first_spare_pdb_parameter | forty-first spare pdb parameter - string list |
| _forty-fourth_spare_pdb_parameter | forty-fourth spare pdb parameter - string list |
| _forty-ninth_spare_pdb_parameter | forty-ninth spare pdb parameter - string list |
| _forty-second_spare_pdb_parameter | forty-second spare pdb parameter - string list |
| _forty-seventh_spare_pdb_parameter | forty-seventh spare pdb parameter - string list |
| _forty-sixth_spare_pdb_parameter | forty-sixth spare pdb parameter - string list |
| _forty-third_spare_pdb_parameter | forty-third spare pdb parameter - string list |
| _fourteenth_spare_pdb_parameter | fourteenth spare pdb parameter - integer |
| _fourth_spare_pdb_parameter | fourth spare pdb parameter - integer |
| _fsdirect_fast_file_create | Allow optimized file creation path for FsDirects |
| _gc_disable_cell_populate | if TRUE, disable cell ram cache populate |
| _gc_down_convert_after_write | if TRUE, down-convert lock after a write |
| _gc_fast_index_split_timeout | fast index split wait timeout |
| _gc_rdma_connections | maximum number of buffer cache RDMA connections |
| _gc_undo_header_rdma_read | if TRUE, rdma read of undo headers is enabled |
| _gcr_disabled_actions | gcr disabled actions list |
| _gcr_disabled_metrics | gcr disabled metrics list |
| _gcr_enable_async_slaves | if TRUE, GCR will spawn slave actions asynchronously |
| _gcr_enable_ktfbue_gather_stats | enable/disable gather stats on X$KTFBUE |
| _gcr_enable_pdb_abort | if TRUE, GCR will process pdb abort messages |
| _gcr_ges_cachedres_mult | ges cached resources multiplier |
| _gcr_ges_longchain_mult | ges longchain multiplier |
| _gcr_high_cpwt_threshold | longest tolerable ctwr process waits time |
| _gcr_high_fbwt_threshold | longest tolerable free buffer waits time |
| _gcr_high_hashlist_latch_nowait_misses | highest hash list get nowait fails tolerable |
| _gcr_high_hashlist_latch_wait_misses | highest hash list get wait fails tolerable |
| _gcr_high_lfsci_threshold | longest tolerable log file switch (checkpoint incomplete) wait |
| _gcs_current_rdma | if greater than 0, rdma read of current blocks is enabled |
| _gcs_current_rdma_grant_global | if TRUE, enable rdma read of current blocks for global role |
| _gcs_dynamic_sga_preference | gcs dynamic sga preference |
| _gcs_spin_check_threshold | spin check attempt count |
| _gcs_spin_check_time_interval | spin check time interval in seconds |
| _gcs_verify_antilock | if TRUE, enable anti-lock check |
| _ges_optimizations | GES optimizations level |
| _gsm_srvctl_diag_time | gsm invoked srvctl pre-timeout diagnostic time |
| _gsm_srvctl_timeout | gsm invoked srvctl timeout |
| _gwm_disable_ra | Oracle internal parameter |
| _gwm_lagtype | gsm lag type |
| _gwm_spare1 | gsm spare 1 |
| _gwm_sys_ddl | allow DDL as SYS |
| _gwm_use_srvctl | use srvctl for service mnagement |
| _gws_catalog_wallet | the sharding catalog has a wallet |
| _gws_encddl | Encrypt DDL text. |
| _hang_analyze_elapsed_time_limit | Hang Analyze elapsed time limit in seconds |
| _hang_bool_spare3 | Hang Management bool 3 |
| _hang_cpu_hung_thresh_sec | Hang Manager threshold for resmgr:cpu quantum |
| _hang_fast_tracked_hang_verification_interval | Hang Manager fast-track hang verification interval |
| _hang_high_session_count_update_hb_threshold | Hang Manager high session count update heartbeat threshold |
| _hang_int_spare3 | Hang Management int 3 |
| _hang_low_wait_time_cutoff | Hang Management low wait time cutoff in seconds |
| _hang_mark_some_idle_waits_terminal | Hang Management mark some wait events as terminal waits |
| _hang_max_local_db_clients_allowed | Hang Manager maximum local db clients allowed |
| _hang_px_resolution_on_asm_enabled | Hang Management px resolution on ASM enabled |
| _hang_resolution_partial_hangs_on_asm_enabled | Hang Management resolution of partial hangs on ASM enabled |
| _hang_sess_enq_wait_blocked_session_threshold | Hang Management session enqueue wait blocked session threshold |
| _hang_sess_enq_wait_resltn_trig_time | Hang Management session enqueue wait resolution trigger time |
| _hcs_disable_all_qry_optz | skip all query optimization on generated SQL |
| _hcs_disable_audit_opt | disable audit optimization |
| _hcs_disable_av_sql_hint | disable analytic view sql hint |
| _hcs_disable_calc_union_opt | disable calc union optimization |
| _hcs_disable_dt_opt_cell_qry | disable cell query optimizations for datatype queries |
| _hcs_disable_inline | add inline hint to star block |
| _hcs_disable_merge_fltr_star_opt | disable merge filter star optimization |
| _hcs_disable_no_bdfltrd_opt | apply no base data filtered optimization |
| _hcs_disable_prune_unslvd_star_opt | disable prune unsolved star optimization |
| _hcs_disable_smooth_noop_descendants | perform smooth no-op descendants |
| _hcs_disable_sql_plan_baselines | disable sql plan baselines |
| _hcs_disable_use_cache_star_opt | disable use cache star optimization |
| _hcs_disable_xform_gby | disable transform group by |
| _hcs_enable_adw | enable ADW |
| _hcs_enable_av_auto_cache | enable AV auto-cache |
| _hcs_enable_basetbl_transform | enable base table transform |
| _hcs_enable_code_trc | enable code tracing |
| _hcs_enable_cube_join | enable cube join |
| _hcs_enable_fact_rows | enable fact rows |
| _hcs_log_max_segments | maximum number of HCS log segments, 0 for unlimited |
| _hcs_log_segment_size | HCS log segment size in MB |
| _hcs_max_mdx_cursors | maximum number of MDX cursors |
| _hcs_mdx_sim_sga_alloc_err | simulate mdx sga allocation error |
| _hcs_mdx_sim_so_fail | simulate state object failure |
| _hcs_mdx_sleep_loc | mdx location to sleep for testing |
| _hcs_sim_sqlopt_err | simulate sql optimization error |
| _hstpr_prediction_interval | resource SO prediction interval |
| _hstpr_use_linear_prediction | use session SO lin-reg prediction |
| _hstpr_use_periodic_prediction | use session SO periodic prediction |
| _http_port | HTTP port number registered with local listener |
| _idle_session_scan_frequency | Idle session scan frequency (in seconds) |
| _ignore_pdb_listener | ignore pdb listener |
| _ignore_svc_name_conv_mismatch | Suppress ORA-65174 for service_name_convert clause mismatch |
| _imado_enable_coloptim | Enable AIM Column level optimizations |
| _imado_enhancements | AIM enhancements |
| _imr1_slave | IMR1 slave |
| _imr_slave_debug | IMR slave debug flags |
| _imtxnrma_table_flags | In-Memory RMA Txn Table cache Flags |
| _increase_lmd_process | modifying this hidden parameter, will modify the numberof lmd process by the valueof this parameter |
| _inmemory_dynamic_scans_result_buffers | No. of LWT allocated result buffers per thread |
| _inmemory_hpk4sql_debug | In-Memory HPK4SQL debug |
| _inmemory_hpk4sql_filter_threshold | In-Memory HPK4SQL filter threshold |
| _inmemory_hpk4sql_flags | In-Memory HPK4SQL flags |
| _inmemory_hpk4sql_kv_seg_size | In-Memory HPK4SQL kv segment size |
| _inmemory_hpk4sql_partbuf_maxrow | In-Memory HPK4SQL partbuf maxrow |
| _inmemory_hpk4sql_partbuf_minrow | In-Memory HPK4SQL partbuf minrow |
| _inmemory_hwm_expansion_rac | If 0, the highwatermark CU is dropped when expanded |
| _inmemory_hwm_inv_blocks_threshold | If 0, expansion will occur even for very small hwm imcu |
| _inmemory_hybrid_selectivity_threshold | Selectivity threshold for a qualifying query to enable hybrid IM scans |
| _inmemory_opaque_contig_space_percent | Contiguous memory for opaque VC as a percent of hard maximum |
| _inmemory_populate_blocks_threshold | If 0, scan triggers populate for any missing blocks |
| _inmemory_trickle_populate | Enable inmemory trickle populate |
| _instant_file_create_exascale | enable instant file creation on Exascale |
| _ipc_emu_aop_timeout | static emu AOP tinmeout |
| _ka_lma_msg_wait_count | KA maximum number of requests to retrieve per OSD wait by LMA |
| _ka_lma_wait_time | KA wait time for skjcxWait call by LMA process in microseconds |
| _kcb_reused_max | reused array max parameter |
| _kcrfwrma_flags | KCRFWRMA Flags |
| _kdlf_fast_move_compressed_lob | kdlf fast move commpressed lobs |
| _kdlf_layers_cache | enable kdlf securefiles layers cache |
| _kdli_adaptive_cache_inode | enable adaptive inode cache |
| _kdli_cache_inode_off_limit | cache_off limit for adaptive inode cache |
| _kdlwp_memory_check | bug 31354021: memory diagnostics |
| _kdmado_partial_pop_backoff_mb | AIM Backoff for partial populate |
| _kebm_preshut_act_enabled | Enable/disable MMON Pre-shutdown Action |
| _keep_relocated_source_pdb | Move source pdb to unplugged state after relocation |
| _kffmof_fprate | acceptable false positive rate [1-10000] of the kffmof bloom filter |
| _kffmof_size | number of entries of the kffmof opened files bloom filter |
| _kffmop_list_check | enable PGA mop list sanity check |
| _kgl_bucket_bitvector | Enable creation of PDB bit vector in KGL Hash Buckets |
| _kgl_bucket_bitvector_clear | Enable clearing library cache bucket bit vector |
| _kjac_direct_path_enabled | If direct path is enabled for TG |
| _kkpap_zm_pruning_cache | cache result of recursive zonemap partition pruning query |
| _kkpox_prtmv_rel_lock | explicitly release PRTMV heap during cursor compile |
| _kks_always_check_bind_equivalence | Check bind equivalence every time |
| _kqr_hot_copy_sample_size | number of mutex gets between periodic checks for hot objects |
| _kqr_hot_copy_sleep_limit | threshold of mutex sleeps to enable object hot copies |
| _kqr_max_hot_copies | upper limit of object hot copies allowed |
| _kse_snap_ring_record_min | minimize recorded information in error stack history |
| _ksfdx_tests | ksfdx testing - INTERNAL USE ONLY! |
| _ksfqp_row_count | row count of x$ksfqp |
| _ksipc_ipclw_rcvbuf_mb | Configure IPCLW RCVBUF SIZE (in MB) |
| _ksmsq_conn_per_epoch | KSMSQ Connections Per Epoch |
| _kspmx_enabled | KSPMX Is Enabled |
| _kspmxs_flush_cache_size | KSPMXS flush cache size |
| _kspmxs_latch_freelists | Number of managed PMEM latch freelists |
| _kspmxs_latch_usid_map_size | KSPMXS latch usid map size |
| _kspmxs_max_regions | KSPMXS max regions |
| _kspmxs_max_waits | KSPMXS max waits |
| _kspmxs_txn_freelists | Number of PMEM transactions freelists |
| _kspmxs_upgrade_mutexes | KSPMXS upgrade mutex |
| _kspmxs_usid_map_size | KSPMXS usid map size |
| _kspmxs_wait_buckets | KSPMXS wait buckets |
| _ksr_control_dyn_flags | KSR dyanamic control flags |
| _ksr_control_flags | KSR control flags |
| _ksu_proc_percent_target | dynamic process usage target |
| _ksu_proc_percent_threshold | dynamic process usage threshold |
| _ksws_alb_block_service | enable ALB Blocking of overloaded service |
| _ksws_alb_session_age | KSWS ALB Minimum age(seconds) of session to consider marking |
| _ksws_alb_test_delta_override | KSWS ALB total sessions after which service is blocked |
| _ksws_alb_test_drain_timeout | KSWS ALB time in seconds before draining kicks in |
| _ksws_alb_test_load_balance_frequency | KSWS ALB Load Balance Frequency in deci seconds |
| _ksws_alb_test_load_percent | KSWS ALB Load Percentage to trigger marking for draining |
| _ksws_alb_test_selection_bias | KSWS ALB percentage of sessions to target |
| _ksws_enable_alb | enable ALB metrics processing |
| _ksws_fallback_to_root | KSWS Fallback to Root CDB service |
| _ksws_modsvc_call_out_enabled | modify service call out enabled |
| _ksws_rlb_cpu_busy_scope | KSWS RLB CPU BUSY SCOPE |
| _ksws_use_placement_template_attribute | use placement_template attribute |
| _kswsas_pdb_auto_close_timeout | Close a PDB after the timeout |
| _ksxp_poll_netintr_timeout | ksxp poll network interrupt timeout in seconds |
| _ksz_dummy_parameter | Internal spare parameter for ksz.c |
| _ksz_dummy_parameter2 | Internal spare parameter2 for ksz.c |
| _ktte_ts_shrink_group | tablespace shrink group |
| _ktte_ts_shrink_interval | tablespace shrink interval |
| _ldap_use_all_direct_groups_only | LDAP use all direct groups only |
| _ldap_warning_on_multi_shared_mappings | LDAP warning on multiple shared mappings |
| _link_ts_force_online | force linked tablespace to be online |
| _listener_registration_retry_secs | listener registration retry time (in seconds) |
| _lm_async_da | enable async da requests |
| _lm_comm_send_proxy_nr_delay | Send proxy delay before sending NULLREQ |
| _lm_comm_send_proxy_tkt_return | Allow send proxy to return tickets |
| _lm_comm_slow_op_spx_loop_threshold | GES comm slow spx operation loop threshold in microsec |
| _lm_comm_tkts_adpt_rsv | Adpative ticketing reserve multiple |
| _lm_da_win_enable | enable da windowing |
| _lm_da_window | number of windows in domain action |
| _lm_da_window_interval | Interval in centiseconds between each domain action window |
| _lm_default_failure_action | default failure action |
| _lm_enable_pdb_abort | enable pdb abort as default failure action |
| _lm_gcs_rht_alloc_size | gcs rht allocation chunk size |
| _lm_ges_rht_alloc_size | ges rht allocation chunk size |
| _lm_ges_rht_mem_pct | options to size RHT structures per pdb |
| _lm_hb_lgio_timeout | LGWR io timeout in seconds |
| _lm_mp_additional_big_buffers | GES MP extra big buffers per pool |
| _lm_mp_additional_reg_buffers | GES MP extra regular buffers per pool |
| _lm_mp_expand_big_pool_percent | GES MP expand big pool |
| _lm_mp_expand_reg_pool_percent | GES MP expand regular pool |
| _lm_mp_share_lms_pools | GES MP share LMS pools with critical BGs |
| _lm_mp_small_lms_pools | GES MP small regular pool for LMS when not sharing |
| _lm_new_esm | use new enter server mode code |
| _lm_pdb_weight_opts | options to size RHT structures per pdb |
| _lm_receiver_type | receiver thread type performing receive function |
| _lm_recovery_pdbw_reduction | recovery member pdbw reduction |
| _lm_resource_recycle_cnt | GES: number of resources to recycle optimization |
| _lm_sp_slave_mode | sendproxy slave operation mode |
| _lm_wrkr_mode | LMS worker thread mode |
| _lm_wrkr_slaves | number of LMS worker slaves |
| _lmhb_max_dynamic_hb | max number of proc heartbeats that can be dynamically monitored |
| _log_switch_tracing_iterations | no. of iterations to trace after logswitch timeout |
| _log_switch_tracing_timeout | dbwr to trace after logswitch timeout in secs |
| _max_dynamic_processes | max dynamic processes count |
| _max_flashback_shrink_size | maximum size(in KBs) a datafile can be shrunk with flashback DB |
| _max_gg_extracts | maximum limit for goldengate extract instances |
| _mdapi_transform_engine | DDL transformation engine |
| _mle_compilation_errors_are_fatal | failed compilations are fatal for MLE |
| _mle_compile_immediately | force compilation for MLE |
| _mle_enable_compilation | enable runtime compilation for MLE |
| _mv_logical_partition_rewrite_enabled | enable/disable Logical Partition based rewrite |
| _mv_logical_partition_tracking_enabled | enable/disable Logical Partition Tracking |
| _mv_master_lock_timeout | timeout that mv create/drop waits to lock the master table |
| _ndb_enable | Native Database Blockchain Enable |
| _nineteenth_spare_pdb_parameter | nineteenth spare pdb parameter - integer |
| _ninth_spare_pdb_parameter | ninth spare pdb parameter - integer |
| _non_blocking_hard_parse_min_extend_time | minimum additional lifetime added to cursor |
| _number_ksim_group_req_threshold | ksim maximum number of group operations requests |
| _numgrans_per_file | Number of granules per SGA file |
| _nusa_data_containers | list of data containers in the nusa universe |
| _nusa_metadata_store | metadata store in nusa |
| _nvmeof_zcopy_enable | Enable Zero Copy for NVMeoF |
| _object_activity_control | controls tracing for object activity tracking system (OATS) |
| _object_activity_disable | disables some object activity tracking (OATS) |
| _object_activity_tracking | enable object activity tracking system (OATS) |
| _obsolete_result_cache_mode | USERS SHOULD NOT SET THIS! Used for old qksced parameterof result_cache_mode |
| _ofs_read_buffer_size | OFS read ahead buffer size in bytes |
| _one-hundred-and-forty-first_spare_parameter | one-hundred-and-forty-first spare parameter - boolean |
| _one-hundred-and-forty-second_spare_parameter | one-hundred-and-forty-second spare parameter - boolean |
| _one-hundred-and-forty-third_spare_parameter | one-hundred-and-forty-third spare parameter - boolean |
| _onl_ddl_progress | track progress of online ddl |
| _onl_pmo_wait_query | online pmos wait for queries after swapping partitions |
| _onl_pmo_wait_timeout | online pmos wait for queries after swapping partitions timeout |
| _online_pmo_global_index_method | Unique global index method for partition maintenance DDLs |
| _optimize_dvconfig_cloudpdb | Optimize Database Vault setup for cloud PDB |
| _optimizer_exists_to_any_rewrite | consider exists-to-any rewrite of subqueries |
| _optimizer_nested_loop_join | favor/unfavor nested loop join |
| _optimizer_unnest_update_set_subq | enables unnesting of subquery in set for update |
| _optimizer_use_stats_models | use optimizer statistics extrapolation models |
| _optimizer_wc_filter_pushdown | enable/disable with clause filter predicate pushdown |
| _oracle_script_counter | Helper parameter to set the value of _oracle_script counter |
| _partial_log_preserve_space | use only required space for partial archive logs |
| _path_prefix_create_dir | Create path in file system for CREATE DIRECTORY with PATH_PREFIX |
| _pdb_char_set_intconv | Enforce internal_convert for PDB character set conversion |
| _pdb_clone_preserve_guid | Use same guid for a pdb clone |
| _pdb_create_use_sysoper_conn | spread file copy slaves across instances |
| _pdb_datapatch_violation_restricted | Open pdb in restricted mode for datapatch error violation |
| _pdb_file_copy_affinitize | spread file copy slaves across instances |
| _pdb_file_copy_buffers | number of buffers to use for pdb file copy |
| _pdb_hybrid_read_only | Hybrid read only mode allows CDB common user to patch the PDB |
| _pdb_ktg_buffer_size | KTG buffer size (in KB) to store inmemory traces |
| _pdb_oper_trace_threshold | PDB operations timing trace threshold |
| _pdb_oper_trace_threshold_softassert | PDB operations timing threshold soft assert |
| _pdb_read_only_refresh | allow refresh when pdb is open r/o |
| _pdb_refresh_use_dblink_to_catalog | Use central catalog for pdb refresh |
| _pdb_refresh_use_local_logs | Use local logs for pdb refresh |
| _pdb_small_table_threshold | lower threshold level of table size for direct reads in a pdb |
| _pdb_transition_clean_bg_delay | delay in GEN0 to transition PDB to clean state |
| _pmem_exchange_cold_victim_threshold | worthy touch count threshold for a victim buffer to be exchanged into pmem |
| _pmem_small_table_threshold | lower threshold of PMEM table size as percentage to PMEM cache for direct reads |
| _pmemfs_alloc_dataptrs | Set PMEMfs to preallocate inode tree |
| _pmemfs_enable_spacetracking | Enable PMEMfs Space Accounting Checks |
| _pmemfs_shrink_level | Enable pmemstore shrink |
| _pmemfs_smallfile_threshold | Block count threshold for metedata |
| _post_run_job_evaluation | Control if jobs should evaluate at end of execution |
| _pqq_pdb_load_publish_threshold | difference in percentage controlling PDB load publish |
| _process_max_pred_increase | process SO max predicted increase |
| _process_percent_rampup_end | process SO percent rampup end |
| _process_percent_rampup_start | process SO percent rampup start |
| _process_prediction_failover_buffer | process prediction failover buffer |
| _process_save_prediction | save process prediction for next instance startup |
| _process_so_max_inc | process SO max inc |
| _profile_sensitive_users | Database Users with restricted password profile |
| _psdclog_enable | Mandatory Cloud Logging of PL/SQL Utility Packages Usages |
| _psdclog_threshold | Threshold for Cloud Logging of PL/SQL Utility Packages Usages |
| _psr_opt | options for standby pdb recovery |
| _px_adaptive_dist_nij_enabled | enable adaptive distribution methods for left non-inner joins |
| _px_extended_join_skew_handling | enables extended skew handling for parallel joins |
| _px_oneslave_per_instance_parse | send parse to one slave per instance |
| _px_parallelize_non_native_datatype | enable parallelization for non-native datatypes |
| _remote_http_port | HTTP port number registered with remote listener |
| _reset_increase_lmd_process | set to true to allow reset of _increase_lmd_process changes |
| _reset_increase_lms_process | set to true to allow reset of _increase_lms_process changes |
| _result_cache_do_recycle_period | Timeout value for DOs added through invalidation |
| _result_cache_global_send | Is global send conditional in RAC? |
| _result_cache_history_size | memory used to track PL/SQL function history |
| _result_cache_latch_count | number of result cache latches |
| _result_cache_load_rate | Simulated global load rate (bytes per 1/100 sec) |
| _result_cache_object_black_list | object numbers not allowed to use the result cache |
| _result_cache_use_hash_table | whether to use hash table for object tracking |
| _root_clone_skip_trigger | Skip trigger in Application Root Clone |
| _rsrc_cpu_count | CPU Count for allocating resources. |
| _runtime_index_key_length_check | allow runtime checking of index key length |
| _runtime_limit_parallel_fptr | run-time limit for for parallel first-pass recovery |
| _second_spare_pdb_parameter | second spare pdb parameter - integer |
| _securefile_shrink_enable_nowaitlck | Enable Securefile Shrink NOWAIT row locking |
| _securefile_shrink_hash_table_limit | Size limit on Securefile Lob Shrink state Hash table |
| _securefiles_dealloc_cfs | securefiles deallocate directly to CFS |
| _sess_sign_num_pools | session signature: number of pools |
| _sess_template_all_overflow | session template: put all attributes into overflow |
| _sess_template_cache_buckets | session template: number of cache buckets |
| _sess_template_enabled | session template: enabled |
| _sess_template_max_cache_size | session template: max cache size (in 1/100% of SGA) |
| _sess_template_new_lists | session template: number of new lists |
| _sess_template_purge_time_mins | session template: purge time (in minutes) |
| _sess_template_spares | session template: spares |
| _session_limit_percent_cap | session limit percent cap |
| _session_modp_list | send session's modified parameter list to client |
| _session_so_max_inc | session SO max inc |
| _seventeenth_spare_pdb_parameter | seventeenth spare pdb parameter - integer |
| _seventh_spare_pdb_parameter | seventh spare pdb parameter - integer |
| _seventieth_spare_pdb_parameter | seventieth spare pdb parameter - boolean |
| _shard_ddl_policy | DDL execution mode for shards |
| _shard_sesscache_cnt | enable session caching for shard SQL |
| _singleton_service_goodness_disabled | singleton srvc goodness |
| _sixteenth_spare_pdb_parameter | sixteenth spare pdb parameter - integer |
| _sixth_spare_pdb_parameter | sixth spare pdb parameter - integer |
| _sixtieth_spare_pdb_parameter | sixtieth spare pdb parameter - boolean |
| _sixty-eighth_spare_pdb_parameter | sixty-eighth spare pdb parameter - boolean |
| _sixty-fifth_spare_pdb_parameter | sixty-fifth spare pdb parameter - boolean |
| _sixty-first_spare_pdb_parameter | sixty-first spare pdb parameter - boolean |
| _sixty-fourth_spare_pdb_parameter | sixty-fourth spare pdb parameter - boolean |
| _sixty-ninth_spare_pdb_parameter | sixty-ninth spare pdb parameter - boolean |
| _sixty-second_spare_pdb_parameter | sixty-second spare pdb parameter - boolean |
| _sixty-seventh_spare_pdb_parameter | sixty-seventh spare pdb parameter - boolean |
| _sixty-sixth_spare_pdb_parameter | sixty-sixth spare pdb parameter - boolean |
| _sixty-third_spare_pdb_parameter | sixty-third spare pdb parameter - boolean |
| _skip_oradism_check | Switch on all features for the purpose of testing |
| _skip_sequence_cache_close_immediate | Skip sequence cache flush on pdb shutdown immediate |
| _smon_ofd_sleep_interval | smon sleep internval for undo ofd test |
| _spec_replace_locks_body | Lock body when replacing a package specification |
| _sqlexec_aggregation_settings | runtime settings for aggregation |
| _sqlexec_hash_aggr_small_mem_blocks | hash aggregation small initial memory footprint number of blocks |
| _sqlexec_hash_based_distagg_ser_civ_enabled | enable hash based distinct aggregation in serial/CIV queries |
| _sqlexec_hash_based_set_operation_enabled | enable/disable hash based set operation |
| _sqlexec_hash_rollup_enabled | enable hash rollup |
| _sqlexec_use_delayed_unpacking | enable/disable the usage of delayed unpacking |
| _strict_utl_http_smtp | Enforce strict URL checks on UTL_HTTP and UTL_SMTP Packages |
| _subquery_pruning_flags | subquery pruning flags |
| _swat_ver_mv_knob | Knob to control MV/REWRITE behavior |
| _symbol_no_translation | disable symbol tranlations in call stacks |
| _sync_error_handler | error handler function for Application Sync |
| _synchronous_rewrap_rac_ts_keys | if TRUE, synchronously rewrap TS keys in all nodes in MK rekey |
| _system_memory_simulate | system memory simulation mode, TRUE for hugetlbfs simulation |
| _tcpinfo_statistics_save_atexit | TCP Info Statistics Save At Exit |
| _temp_undo_disable_refresh_clone | is temp undo disabled on refreshable clone PDB |
| _tenth_spare_pdb_parameter | tenth spare pdb parameter - integer |
| _test_flashback_shrink | test flashback datafile shrink feature |
| _test_param_13 | test parmeter 13 - boolean |
| _test_param_14 | test parmeter 14 - string list |
| _test_param_15 | test parmeter 15 - integer |
| _test_param_4_1 | test parameter 4_1 - nonsys mod. string list |
| _test_param_pdb_spare | test parameter pdb spare |
| _test_param_spare | test parameter spare |
| _third_spare_pdb_parameter | third spare pdb parameter - integer |
| _thirteenth_spare_pdb_parameter | thirteenth spare pdb parameter - integer |
| _thirtieth_spare_pdb_parameter | thirtieth spare pdb parameter - string |
| _thirty-eighth_spare_pdb_parameter | thirty-eighth spare pdb parameter - string |
| _thirty-fifth_spare_pdb_parameter | thirty-fifth spare pdb parameter - string |
| _thirty-first_spare_pdb_parameter | thirty-first spare pdb parameter - string |
| _thirty-fourth_spare_pdb_parameter | thirty-fourth spare pdb parameter - string |
| _thirty-ninth_spare_pdb_parameter | thirty-ninth spare pdb parameter - string |
| _thirty-second_spare_pdb_parameter | thirty-second spare pdb parameter - string |
| _thirty-seventh_spare_pdb_parameter | thirty-seventh spare pdb parameter - string |
| _thirty-sixth_spare_pdb_parameter | thirty-sixth spare pdb parameter - string |
| _thirty-third_spare_pdb_parameter | thirty-third spare pdb parameter - string |
| _trace_suppress | suppresses matching trace for a given substring(prefix) |
| _trace_suppress_disable | Disable trace suppress feature |
| _ttc_annotations_level | enable ttc annotations |
| _twelfth_spare_pdb_parameter | twelfth spare pdb parameter - integer |
| _twentieth_spare_pdb_parameter | twentieth spare pdb parameter - integer |
| _twenty-eighth_spare_pdb_parameter | twenty-eighth spare pdb parameter - string |
| _twenty-fifth_spare_pdb_parameter | twenty-fifth spare pdb parameter - string |
| _twenty-first_spare_pdb_parameter | twenty-first spare pdb parameter - string |
| _twenty-fourth_spare_pdb_parameter | twenty-fourth spare pdb parameter - string |
| _twenty-ninth_spare_pdb_parameter | twenty-ninth spare pdb parameter - string |
| _twenty-second_spare_pdb_parameter | twenty-second spare pdb parameter - string |
| _twenty-seventh_spare_pdb_parameter | twenty-seventh spare pdb parameter - string |
| _twenty-sixth_spare_pdb_parameter | twenty-sixth spare pdb parameter - string |
| _twenty-third_spare_pdb_parameter | twenty-third spare pdb parameter - string |
| _txn_spare1 | transaction spare variable1 |
| _txn_spare2 | transaction spare variable2 |
| _txn_spare3 | transaction spare variable3 |
| _undo_ofd_enabled | enable ordered offline drop of undo segments for datafile shrink |
| _undo_ofd_excess | percent of excess undo segments to offline or drop |
| _undo_ofd_reserve | percent of excess undo segments to keep online |
| _unified_pga_block_size | Unified PGA internal block size |
| _unified_pga_gran_free_timeout | Granule free timeout |
| _unified_pga_gran_leak_timeout | Granule leak timeout |
| _unified_pga_list_count | Unified PGA internal list count |
| _unified_pga_max_pool_size | max size in bytes of the unified pga pool |
| _upgrade_pdb_on_open | Enable upgrading a PDB automatically on open |
| _ut_fast_lrg_prediction | use short interval for session SO prediction |
| _utlfile_dirpath | return Utl_File Accessible |
| _uts_disable_client_ip_trace | Disables the printing of client IP address in trace files |
| _uts_force_seclabel_prefix | Force output of trace record security label prefix |
| _write_renamed_datafile_name | print renamed datafile names to alert log |
| _xs_sidp_allow_sha1 | XS SIDP allow use of SHA1 |
| _zonemap_auto_candidate_table_min_size | Minimum size for a table to be candidate for an automatic zonemap |
| _zonemap_auto_clustering_ratio | Data clustering ratio in percent for automatic zonemap columns |
| _zonemap_refresh_within_load | Control the refresh of basic zonemaps during/after data load |
Parameters deprecated in Version 21c in comparison with 19c
| NAME | ISDEP | DESCRIPTION |
|---|---|---|
| lock_name_space | TRUE | lock name space used for generating lock names for standby/clone database |
| instance_groups | TRUE | list of instance group names |
| resource_manager_cpu_allocation | TRUE | Resource Manager CPU allocation |
| active_instance_count | TRUE | number of active instances in the cluster database |
| db_block_buffers | TRUE | Number of database blocks cached in memory |
| buffer_pool_keep | TRUE | Number of database blocks/latches in keep buffer pool |
| buffer_pool_recycle | TRUE | Number of database blocks/latches in recycle buffer pool |
| log_archive_start | TRUE | start archival process on SGA initialization |
| fast_start_io_target | TRUE | Upper bound on recovery reads |
| serial_reuse | TRUE | reuse the frame segments |
| rdbms_server_dn | TRUE | RDBMS's Distinguished Name |
| cursor_space_for_time | TRUE | use more memory in order to get faster execution |
| plsql_v2_compatibility | TRUE | PL/SQL version 2.x compatibility flag |
| plsql_debug | TRUE | PL/SQL debug |
| background_dump_dest | TRUE | Detached process dump directory |
| user_dump_dest | TRUE | User process dump directory |
| commit_write | TRUE | transaction commit log write behaviour |
| sql_trace | TRUE | enable SQL trace |
| parallel_adaptive_multi_user | TRUE | enable adaptive setting of degree for multiple user streams |
| asm_preferred_read_failure_groups | TRUE | preferred read failure groups |
Hidden Parameter Not Available in 21c in comparison with 19c
| PARAMETER | PARAMETER_DESCRIPTION |
|---|---|
| _arch_sim_mode | Change behavior of local archiving |
| _asm_enable_parity_datafile_creation | Enable parity datafiles creation |
| _auto_start_pdb_services | Automatically start all PDB services on PDB Open |
| _bug29274428_modsvc_call_out_enabled | one-hundred-and-forty-third spare parameter - boolean |
| _connect_string_params_after_logon_triggers | set connect string session parameters after logon triggers |
| _connect_string_params_unalterable | make connect string session parameters unalterable |
| _disable_thread_snapshot | Thread snapshot |
| _enable_auto_upgrade | Enable automatic PDB upgrade |
| _gc_async_receive | if TRUE, receive blocks asynchronously |
| _group_partition_data_for_impdp_ok | data pump import allows DATA_OPTIONS=GROUP_PARTITION_DATA |
| _hang_enable_nodeeviction | Enable Hang Manager node eviction |
| _hang_long_wait_time_threshold | Long session wait time threshold in seconds |
| _hcs_disable_cell_qry_meas_prune_opt | apply measure prune optimization to cell query |
| _hcs_disable_cell_qry_tmpls | no cell query templates for optimization |
| _hcs_disable_hord_in_oby_prune | prune levels if HIER_ORDER referenced only in ORDER BY |
| _hcs_disable_jback_opt_for_hord_in_oby | optimize analytic view joinback for HIER_ORDER |
| _hcs_disable_level_prune_gby | perform level pruning in group by |
| _hcs_disable_level_prune_vis_lvs | perform level pruning from visible leaves |
| _hcs_disable_pushed_preds_in_gen_sql | push sql query predicates into hierarchy targets |
| _hcs_disable_rmv_unref_top_opt | apply remove unref top blocks optimization to cell query |
| _hcs_disable_sp_jback_opt | optimize single parent joinback |
| _hcs_disable_tgt_depths_opt | apply target depths optimization |
| _hcs_enable_dynamic_cache | enable/disable av cache DYNAMIC definition |
| _hcs_enable_mem_trck | enable memory tracking |
| _hcs_enable_multi_parent_gen | generate hcs query using multi-parent aggregation |
| _kkpo_ctb_allow_vpd | allow VPD predicates in recursive SQL under CREATE TABLE |
| _ksipc_ipclw_spare_param1 | ksipc ipclw spare parameter 1 |
| _log_archive_avoid_memcpy | log archive avoid memcpy |
| _optimizer_auto_index_allow | Controls Auto Index |
| _optimizer_quarantine_sql | enable use of sql quarantine |
| _part_access_version_by_number | use version numbers to access versioned objects for partitioning |
| _pga_detail_combine_auto | combine auto and manual PGA memory detail snapshots |
| _reset_maxcap_history | reset maxcap history periods |
| _securefiles_increase_hbb | securefiles increase hbb |
| _session_fast_lrg_prediction | use short interval for session SO prediction |
| _session_prediction_interval | session SO prediction interval |
| _session_use_linear_prediction | use session SO lin-reg prediction |
| _session_use_periodic_prediction | use session SO periodic prediction |
| _show_mgd_recovery_state | Show internal managed recovery state |
| _size_of_status_table | modifying this hidden parameter, will modify the sizeof the v$gcr_status table |
| _so_max_inc | SO max inc |
| _ta_lns_wait_for_arch_log | LNS Wait time for archived version of ORL |
| _tablespace_encryption_default_algorithm | default tablespace encryption block cipher mode |
| _unified_audit_flush_interval | Unified Audit SGA Queue Flush Interval |
| _unified_audit_flush_threshold | Unified Audit SGA Queue Flush Threshold |
| _workload_attributes_spare_param | connect string workload behavior spare param |
Parameters becomes Obsolete in Version 21c in comparison to 19c
| PARAMETER | PARAMETER_DESCRIPTION |
|---|---|
| sec_case_sensitive_logon | case sensitive password enabled for logon |
| REMOTE_OS_AUTHENT | allow non-secure remote clients to use auto-logon accounts |
| cluster_database_instances | number of instances to use for sizing cluster db SGA structures |
| _group_partition_data_for_impdp_ok | data pump import allows DATA_OPTIONS=GROUP_PARTITION_DATA |
| _zonemap_auto_processing | Control the processing of automatic zonemaps |
| _part_access_version_by_number | use version numbers to access versioned objects for partitioning |
Note: Parameter “_zonemap_auto_processing” was introduced in 20c Preview version and made obsolete in 21c innovation version.
The details of the Parameters are collected from the database views.
| View_Name | Details |
|---|---|
| V$OBSOLETE_PARAMETER | This view shows the information on database Obsolete parameters. |
| V$PARAMETER | This view shows the information for the parameter value that effects for current session level parameter. |
| V$PARAMETER2 | This view is similar to V$PARAMETER view, only difference is view output for value column. Multiple value for same parameter are shown in this view with multiple rows. Example, multiple values for control_files. |
| V$PARAMETER_VALID_VALUES | This view displays a list of valid values for list parameters. |
| V$SPPARAMETER | Its shows the information of SPFILE, if the instance is not brought up with SPFILE then the value of ISSPECIFIED column will be shown as "FALSE". This view also saves the parameter value altered with scope as spfile. |
| V$SYSTEM_PARAMETER | This view contains the instance level parameters, a new user session inherits the parameters from this view. This view also saves the parameter value altered with scope as memory or both. |
| V$SYSTEM_PARAMETER2 | This view shows the system level parameters. |
| V$SYSTEM_RESET_PARAMETER | This view Shows the value of a parameter if you run alter system reset to clear it from spfile. |
| V$SYSTEM_RESET_PARAMETER2 | This view is similar to V$SYSTEM_RESET_PARAMETER view, only difference is in output of value column like of V$PARAMETER2. |
| X$KSPPI | This is a Kernel Service view that have the information on database hidden parameter. |
| X$KSPPCV | This is a Kernel Service view that have the current session level hidden parameter value. |
| X$KSPPSV | This is a Kernel Service view that have the system level hidden parameter value. |
Conclusion:
After going through this blog the information on new parameter introduced and deprecated will be clear and users will be able to use the parameters for Database Version 21c for building a healthy and well performed database.
In the upcoming blogs I will try to illustrate the performance difference for using the database parameters
Nicely put Tapas. This will be a good help for existing DBA administrators..